Date: Thu, 7 Jun 2007 12:24:16 -0400 (EDT) From: "Matthew Hagerty" <matthew@digitalstratum.com> To: "Fluffles" <etc@fluffles.net> Cc: freebsd-hardware@freebsd.org Subject: Re: Promise TX2300 array not detected. Message-ID: <21250.192.85.50.1.1181233456.squirrel@mundomateo.com> In-Reply-To: <46678017.6080602@fluffles.net> References: <4662E72B.70003@digitalstratum.com> <4662F5BF.4090709@razik.de> <4663496A.40202@digitalstratum.com> <466718DC.2030600@razik.de> <46674449.6090109@digitalstratum.com> <46678017.6080602@fluffles.net>
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On Wed, June 6, 2007 11:48 pm, Fluffles wrote: > Matthew Hagerty wrote: > >> Hey Lukas, >> >> >> Thanks for the response! Wow, that seems like a messy procedure, but >> I'll go see if I can get things working. I only have three questions >> at this point: >> >> 1. What is atacontrol doing that lets FreeBSD see the array? >> 2. After using atacontrol, is this now a software or hardware array? >> 3. Is there anyone I can send my card to who can fix FreeBSD? >> > > If i understand correctly, you're using firmware RAID, also called fake > RAID. It's called Fake RAID because the controller itself does not > handle the "RAID thing" but rather leaves it to drivers (software) to > implementent the RAID0/RAID1 handling, just like software RAID would. In > Windows, you get this working by using drivers, whereas for Linux and > BSD often no drivers are provided. Instead, FreeBSD is able to read the > so called "meta information" stored on the drives to read "oh hey this disk > is said to be part of a RAID0 array, and this is disk0 of in total 2 disks > with x KB stripesize". And later it finds the other disk part of the > array, it can then use it's own RAID0 or RAID1 implementation and create > software RAID on it, just like a Windows driver would do it. > > You see, even firmware/fake RAID is still software RAID; its all > implemented in the drivers. The only difference to true software RAID is > that it adds bootstrap support whereas one cannot boot from a software > RAID0 array. So to answer your first two questions: > > > 1) atacontrol is used to create a RAID0 array using manual parameters, > while normally these parameters would be read from the on-disk metadata (in > the drive's last sector) 2) it is and always has been a software array, > also in windows. only if the host OS cannot see the physical disks behind > the controller you're talking about hardware RAID. Those controllers > usually cost over 200 dollar; they are the real thing. So to be quite > blunt.. your hardware controller gives you software RAID, not hardware > RAID. > > > Hope this gives some background. > Good luck, > > > - Veronica > _______________________________________________ > freebsd-hardware@freebsd.org mailing list > http://lists.freebsd.org/mailman/listinfo/freebsd-hardware > To unsubscribe, send any mail to > "freebsd-hardware-unsubscribe@freebsd.org" > Veronica, Thanks for the info. I guess I assumed that once you got BIOS support for the RAID from the controller that you were into the "real deal". Seems that this is not always the case. So, cheap RAID cards only offer boot support - bummer. Why do I always have to learn this stuff the expensive way? ;-) I'm still curious about the "meta data" that atacontrol seems to write, and what possibly changed in the BIOS revision of the TX2300 that FreeBSD used to be able to recognize the arrays, but now can't. I did, however, manage to get the RAID working with atacontrol. Went like this: 1. Set up the array in the TX2300 BIOS. 2. Install FreeBSD from CD on to ad4 only (ad4 and ad6 are the two drives attached). 3. Boot, login as root. 4. Execute: atacontrol create RAID1 ad4 ad6 5. Reboot with install disk in CD. 6. Reinstall on ar0 which is not available. I did not have a live filesystem disc or I could probably have skipped the initial install, but a minimal install only takes 5 minutes so it was not a big deal. After the second install, everything came up on the ar0 array and worked fine. I ran some basic stress tests and was getting 16MB/sec write speed and 46MB/sec read. So, I'm off to find a "real" SATA2 PCI RAID card... :-( Thanks for all the help. Matthew
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